The Role of Sugar
There’s a big culprit in the metabolic process that has popped up in the last 20-30 years—high fructose corn syrup, which has been used in an increasing number of food products since its introduction to the U.S. in 1975. To understand why this is important when it comes to your child’s weight, here’s a short biology and history lesson on the nature of sugar.
First, the history lesson.
Before the late 1970s, we received much of our sugar through natural sources such as fruits, vegetables and honey. To add sugar to our foods, we used cane sugar, which had to be shipped to the U.S. from islands that produced it; therefore, it was limited in the quantity and regulated by cost. In the 1973, an effort was made by the Nixon administration to stabilize and decrease the cost of sugar and other foods. For this and other reasons, corn subsidies were born, and farmers were incentivized to reduce their crop diversification and grow only corn.
At about the same time, the U.S. Department of Agriculture, the Food and Drug Administration and the American Medical Associations announced recommendations to Americans to limit fat intake, after research showed a link between fat consumption and elevated bad cholesterol, or LDL. The low-fat generation was born, and fats were reduced or removed from foods.
Unfortunately, when fat is removed from food, the taste and texture changes dramatically. The food industry realized that something needed to be added to these low fat foods to make them palatable. Enter high-fructose corn syrup, a cheap but tasty sweetener made, conveniently, from an item America has bountiful stores of: CORN. Suddenly, high fructose corn syrup was found in everything, literally from soup to nuts.
If we look back over the last 100 years, the growth of our consumption of fructose has been stunning. In 1900, Americans consumed an average of 15 grams of fructose a day, mainly through fruits, vegetables and honey. Around World War II, soft drink and candy makers started to increase production, and fructose consumption increased to 16-24 grams a day. In 1977, it went up to 37 grams a day—8 percent of our total caloric intake. Then the use of high-fructose corn syrup really caught on and American’s consumption of fructose soared to 55 grams per day—10 percent of caloric intake. Currently, for adolescents, it’s about 73 grams per day, or 12 percent of caloric intake and five times higher what it was in 1900. Even more, one-quarter of adolescents consume at least 15 percent of their calories from fructose (Reference: Gray, American Journal of Political Nutrition, 86: 895: 2007)
Why is the soaring consumption of high-fructose corn syrup a problem?
Here’s where the biology lesson comes in: We simply can’t metabolize fructose as well as glucose. Glucose is utilized by all the cells of the body for energy, and any remainder makes its way to the liver and is stored as a healthy form of energy called glycogen. Fructose, on the other hand, is converted into fat and stored in the liver and in fat cells. Overburdened fat cells secrete nasty chemicals that increase inflammation and turn off fullness signals to the brain. So we eat more fructose, load our fat cells more, get hungrier, and the process continues in a viscous cycle.
What is the difference between table sugar and high fructose corn syrup?
Previously, we used to feel that they were pretty equivalent. Table sugar is sucrose: which is fructose + glucose- in about a 50/50 ratio. High Fructose corn syrup is supposed to be about 50-55% fructose- giving us about the same fructose burden. But recent research has shown sodas in particular are using 65-70% fructose – much higher than previously believed.
What about fruits and vegetables?
They contain sucrose, which breaks down to glucose and fructose. So why don’t they make us fat? The difference: In nature, fructose is always accompanied by fiber, which decreases the absorption rate, and makes us fuller faster so we consume less fructose as a whole. Now you understand how, by going on low fat diets, we have actually gotten fatter!
So what do you do with this information?
Focus on eliminating as much fructose from your diet as possible– especially in the form of high fructose corn syrup. If you take in fructose, make sure it is accompanied by fiber– such as in the fructose in fruits and veggies. This is why we focus so hard on changing your fluids to water and low fat milk from soda, juices, and other sugar sweetened beverages. It is also why we recommend switching from low fiber “whites” to high fiber whole grains.